The advent of food processing has long since revolutionized both the availability of foods as well as the expectation of consumers for a large variety of high quality food products. One method for processing a large volume of foods, such as, for example, fruits and vegetables, is after selection, to transport these various food stuffs by an aqueous medium to deliver the food stuffs through various processing steps and environments. For example, in specific applications, fresh fruits and vegetables may be transported through water streams by food handling equipment used at the processing plant.
After picking, fruits and vegetables can be introduced into a flume system wherein water acts as a transport medium and a cleaning medium. Water can be used to support and transport the fruits or vegetables from an unloading site to a storage, packing, or processing location. During the transport, water can take a food item from an initial location through a series of somewhat separate stages to a final station where the produce is removed from the water and packed. The water within each stage can have a varying degree of organic load in the form of any number of sediments and soluble materials. This water is generally recycled.
Water can also be used in some of the processing stages to further clean, cool, heat, cook, or otherwise modify the food in some fashion prior to packaging. Process water as defined above may sometimes be used once and discarded. However, often times a major portion of this process water is re-used and is, therefore, subject to organic and microbial contamination. In some stages this process water stream is also used to transport the food. In other stages, the process water may be a separate stream and is recycled apart from the transport water. In either situation, the process water becomes contaminated with organic matter from the food, providing nutrients for microbial growth in the water. Examples of different types of process water are vegetable washers, vegetable cooling baths, poultry chillers, and meat washers.
Given the nature of the food transported as well as the presence of sediments and soluble materials, the water, flume, and other transport or processing equipment may be subject to the growth of unwanted microorganisms. These microorganisms are generally undesirable to the transported food, the water, the flume and may cause buildup on all water contact surfaces of slime or biofilm, which requires frequent cleaning to remove. Further, because the process water and equipment are in contact with food products, the control of unwanted microorganisms presents certain problems created by a food contact environment containing microorganisms.
There are also aqueous streams used to process certain types of food subsequent to packaging. Some foods are often times heated, cooled, or otherwise processed after being placed into packages made of metal, glass, or plastic containers, for example, bottled beer pasteurizers, can cookers, or can coolers. In all cases, contamination of the aqueous streams by food occurs due to leakage from defective packages or spillage on the outside of the package during the packaging operation. These packaged food process streams also are, therefore, subject to unwanted microbial growth and high concentrations of organic matter similar to pre-packaged process and transport water.
Conventional peroxycarboxylic acid compositions, which typically include short chain peroxycarboxylic acids or mixtures of short chain peroxycarboxylic acids and medium chain peroxycarboxylic acids have been used in food transport and processing waters (see, e.g., U.S. Pat. Nos. 5,200,189, 5,314,687, 5,409,713, 5,437,868, 5,489,434, 6,674,538, 6,010,729, 6,111,963, and 6,514,556).
A need exists in the food processing industry to provide a method for food transport and processing which also controls soil and microbial load without the use of high concentrations of antimicrobials such as chlorinated compounds or other halogenated constituents.